Update 0070.爬楼梯完全背包版本.md

Added python version code

problems/0070.爬楼梯完全背包版本.md

@@ -146,7 +146,18 @@ class Solution {
 ```
 
 Python：
-
+```python
+class Solution:
+    def climbStairs(self, n: int) -> int:
+        m = 2
+        dp = [0] * (n + 1)
+        dp[0] = 1
+        for i in range(n + 1):
+            for j in range(1, m + 1):
+                if i >= j:
+                    dp[i] += dp[i - j]
+        return dp[-1]
+```
 
 Go：
 ```go